The meniscus is a semi-circular disk of cartilage that is located in the knee between the shinbone and thighbone. The word posterior is taken from a Latin word that means back or behind. Posterior meniscus is, therefore, located in the back or behind portion of the knee.
There are two menisci in each knee: the lateral meniscus and the medial meniscus. The lateral posterior meniscus, also referred to as the external semilunar fibrocartilage, is located on the outside part of the knee joint. Situated on the inside of the knee joint is the medial posterior meniscus, which also is referred to as the internal semilunar fibrocartilage.
The medial meniscus often is the site where people experience knee pain from a knee injury. The primary function of both the lateral meniscus and the medial meniscus is to provide cushion and support for the knee. When the support fails, it usually results in torn cartilage. A cartilage injury can be extremely painful, especially when it involves tearing. Levels of severity can vary from a slight, barely noticeable tear to the meniscus being torn almost completely away from the knee joint.
Whether or not meniscus surgery is warranted usually depends on several preexisting conditions. Factors typically include the age of the injury, the age of the patient, the overall fitness level of the patient, and the overall health of the patient. Typically, the most important factor when considering surgery is the exact location of the cartilage injury.
Meniscus injuries are categorized into two zones: the red zone and the white zone. The red zone is the outer edge area of the meniscus, and it is called the red zone due to the ample supply of blood in that region. If an injury is minor and located in the red zone, it most likely will not require surgery because these types of cartilage tears generally heal on their own. Large tears in the red zone might require meniscus surgery, but recovery from knee surgery in this zone typically is relatively short.
The white zone, located in the inner region of the posterior meniscus, does not contain an ample supply of blood for prompt healing. Surgery generally is discouraged in this region. If a minor injury occurs in this zone, it typically is left alone to heal. Healing time in this region of the meniscus usually is greater than in the red zone. If the injury merits surgery in this zone, the results are either a partial removal of the meniscus – called a partial meniscectomy – or in some severe cases, the complete removal of the meniscus.
For the most part, the posterior meniscus is a delicate part of the human anatomy and is prone to injury. Whether injury occurs due to strain or over-exertion, immediate symptoms of a cartilage injury usually include knee pain. Addressing the symptoms, taking it easy, and seeing a doctor after injury can be crucial to a healthy recovery.